The present invention relates to a display apparatus for a recording and/or playback device (e.g. an audio tape recorder) which displays the present position of a recording medium (e.g., the present position on the tape at which playback or recording is taking place) as it is running as well as the positions of mark signals (e.g., cue signals) recorded on the recording medium.
In known audio tape recorders, it is common to record cue signals which indicate the starting and ending positions of a dictated item (e.g., a letter) so as to be able to identify the location of a plurality of items recorded on the magnetic tape. This makes it possible to improve the efficiency of the typist by knowing the positions of each item recorded on the magnetic tape and the present point on the magnetic tape at which playback (transcription) is taking place.
One known method and apparatus for achieving this result is disclosed in Japanese Utility Model Publication No. Sho 58/1983-34634. In the disclosed apparatus the present position of the magnetic tape is calculated from the difference in the frequencies of respective pulses generated from the supply and winding reels of the tape as the tape is advanced or rewound (more generally transported) and the position of a cue signal is displayed. In this method, however, the need to detect pulses from the supply and winding reels makes it necessary to provide pulse generators and detectors, which complicates the apparatus and increases its cost.
Another display apparatus is disclosed in Japanese Laid Open Patent Publication No. Sho 54/1979. This apparatus displays cue signals by counting pulses from either of the supply and winding reels and the position of cue signals based on the counted value when a magnetic tape reaches its end. In this method, however, a magnetic tape must be rewound until it reaches its tape end in order to accurately display the relative position of a cue mark signal on the tape. This complicates the operation of the device and it is impossible to accurately provide the relative position of the cue signal while the magnetic tape is being rewound.
The display of the present position of the magnetic tape and the position of a cue signal recorded thereon can be accomplished by providing a display apparatus in which a plurality of light emitting diodes (LED) are arranged in two rows so as to give a visual readout of the positions of the cue signals and the present position of a magnetic tape.
In display apparatus of this kind, it is typical to arrange the intervals one minute apart so as to indicate a present position of a magnetic tape or positions or cue mark signals by lighting or blinking the LEDs corresponding to their positions.
With such an arrangement in which the distance between each LED indicates a period of about one minute, when a cue mark signal is displayed on the fifth LED beyond the LED indicating the present position of the magnetic tape, for example, it is possible to determine that the next cue signal is at a position approximately five minutes after the present position. According to this information, a typist can easily determine that the remaining portion of the item being typed is about five minutes long.
Since the distance between each LED is one minute, the resolution of the display is less than one minute. Accordingly, a display apparatus has been proposed, in which the number of LEDs is increased so as to provide an increased resolution. Alternatively another display apparatus having a high resolution can be added. In addition, a display apparatus has been disclosed in U.S. Pat. No. 4,410,923 in which a plurality of LEDs are arranged in two rows so as to be able to respectively display the present position of the magnetic tape and the position of the cue signal. A numerical display apparatus is also provided which numerically displays the time from the present position to the position of the next cue mark signal.
With such arrangement, since a time period from a present position of a magnetic tape to a position of a cue mark signal can be displayed in a second unit, it is possible to precisely read the residual time period to the next cue mark signal.
As described above, the prior art provides means to improve resolution in a time period for display by increasing the number of LEDs or providing another display apparatus or a numerical display apparatus having high resolution. Such prior art devices, however, make it necessary to provide an extra panel surface and complicates the prior art structure greatly. Accordingly, it is difficult to reduce the size and cost of the structure of the prior art.